Wow – good thing you went early, since it gets hot in Las Vegas! When you use “draw the line at” you then put something you will not do. So you can say, “I draw the line at missing my early morning jog” because you will not miss your morning jog:

I love my daily routine but I can’t keep it due to business trips and other things. But I draw the line at missing my early morning jog. I run everywhere! I even had a run in Las Vegas without gambling!

Great example! In the end I would say, “…I would check the escape route and remember how to follow it.”

A few things: You draw a line “at” something. And I would re-arrange the first two parts of the sentence this way: “If you want to strike the right balance in life, it’s necessary to draw the line at bad habits.”

Perfect example!

Good example! Since this is about your preferences, I’d put this all in the present tense. Also, you would say “draw the line at”:

You can say, “At a restaurant, I can accept it if the food isn’t good or if the facilities aren’t idea, but I draw the line at bad service.”